Report `ABSENT` when there is no value from ART. This is an update to commit 3fb0c3e38b82ea65b65f6ee186098bed02d0809a. The reason of this change is to avoid using `UNSPECIFIED (0)` in all cases. Bug: 423542133 Test: Presubmit Flag: EXEMPT log only update Change-Id: I124676faa8f65a9da80c17c0086d7ad04cd654a9